Evading IDS in exploit development

In the context of buffer overflow exploit development, I was asked:

Discuss how your exploit may be modified to evade an Intrusion Detection System.

I'm not asking for my homework to be done, but after using my best Google-Fu, the only answer I can find is to use encoders (like shikata_ga_nai).

Are there other methods in exploit development for evading IDS?

Given the context, it seems unlikely that this is the only thing I should discuss, but as I said, after spending the evening on it I can't find anything else.